With the RCA wireless 900MHz headphones, you don't even have to be in the same room with your stereo. The signal can pass through walls, floors, and carry outside of your home up to 100 feet. That means you have the freedom to work or relax wherever you wish without the problem of being connected to cords or carrying around a portable system. Features include: 900Mhz frequency 100-ft. effective range (open field) 100-7000Hz frequency response 50dB signal to noise ratio Runs on two AA batteries (not included) Package includes: Wireless headphones AC adapter